Mail Security and Locking Problem

[rjk at mgweed.UUCP]

The following secure mailing scheme works great for us:

Actual transcript of what happens as user "rjk":
-------------------------------------------------------
$ ls -ld /usr/mail
drwxrwx--x   2 bin      mail         960 May 26 09:05 /usr/mail

$ ls -l /usr/mail/rjk
-rw-rw----   1 rjk      mail         417 May 26 09:05 /usr/mail/rjk

$ cat /usr/mail/rjk
>From jfs Thu May 26 09:04:22 1983
To: rjk
Subject: cu
...

$ ls -l /usr/mail/adm
-rw-rw----   1 adm      mail         825 Mar 22 15:30 /usr/mail/adm

$ cat /usr/mail/adm
cat: cannot open /usr/mail/adm

$ ls -l /usr/mail
/usr/mail unreadable
total 2

$ grep MFMODE /usr/src/cmd/mail.c
#define	MFMODE		0660		/* create mode for `/usr/mail' files */
--------------------------------------------------------

No one can read anyone else's mail and the locking mechanism works as it
is supposed to.
							Randy King
							we13!mgweed!rjk